Non-uniform lateral current distribution in quantum cascade lasers.

Non-uniform lateral current distribution in quantum cascade (QC) lasers is investigated, as a result of stimulated-optical-emission-assisted electron transport, the rate of which depends on the local photon density and is comparable to the longitudinal optical (LO) phonon scattering rate. A microscopic model based on rate equations is built to study the self-consistent process of interaction between local electrons and photons in QC lasers. The non-uniform distribution of lateral current and the corresponding spatial hole burning are simulated from this model. Moreover, multi-transverse-mode operation in QC lasers is also investigated.